# 模块开头应有文档字符串，用于描述模块功能
"""一个可用于表示汽车的类"""


class Car:
    """一次模拟汽车的简单尝试"""

    def __init__(self, make, model, year):
        """初始化描述汽车的属性"""
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        """返回整洁的描述性信息"""
        long_name = str(self.year) + " " + self.make + " " + self.model
        return long_name.title()

    def read_odometer(self):
        """打印汽车里程"""
        print("This car has " + str(self.odometer_reading) + " miles on it.")

    def update_odometer(self, mileage):
        """修改里程表读数，并防止里程表读数回调"""
        if mileage >= self.odometer_reading:
            self.odometer_reading = mileage
        else:
            print("You can't roll back an odometer!")

    def increment_odometer(self, miles):
        """将里程表读数增加指定的值"""
        self.odometer_reading += miles

    def fill_gas_tank(self):
        """填满油箱"""
        print("The gas tank is already full!")


# 9.4.2 在一个模块中存储多个类


class Battery:
    """模拟电瓶"""

    def __init__(self, battery_size=70):
        """初始化电瓶的属性"""
        self.battery_size = battery_size

    def describe_battery(self):
        """打印电瓶容量"""
        print("This car has a " + str(self.battery_size) + "-kWh battery")

    def get_range(self):
        """指出电瓶的续航里程"""
        if self.battery_size == 70:
            range = 240
        elif self.battery_size == 85:
            range = 270

        message = "This car can go approximately " + str(range)
        message += " mile on a full charge."
        print(message)


class ElectricCar(Car):
    """模拟电动车"""

    def __init__(self, make, model, year):
        """初始化父类的属性"""
        super().__init__(make, model, year)
        self.battery = Battery()
